I've tried so many variations, I'm not sure what is the best locations anymore. It is just frustrating when you add all these treatments/bass traps, spend countless hours graphing things, purchase additional subs, for what, the graphs aren't showing me much.

Personally, I can tell the bass is more pressurized in the room, and stronger as I walk around. Maybe, my huge room, that is not perfectly rectangular, and the seating is off center, etc. is my problem.

I'm just doubting myself now on what I should do next. Now there is that buzzing problem I mentioned that kicks in as soon as I have all the subs running. I don't know how the heck to fix that.

Regarding your buzzing problem, did you try my suggestion of placing the Denon and the subs all on the same power outlet? If that fixes your problem the issue is grounding. If it doesn't fix your problem, the issue may still be grounding.

John, I forgot to mention I've gone back/forth on using your method of dialing in each sub 5dB below, and then turning them all on, and calibrating them all the same as the other speakers.

The reason why the change is that when listening to music, I was just not getting the WoW affect in the lowww end. Ian's video mentioned to calibrate them all the same, and this seems to give me the lows I would expect from subs. 3 subs should blow me out of the room, and they are not. the only time is if I put on some of those Bass Subwoofer test songs on youtube.

Mojo, I have the new amp but not sure if it is the new firmware, I can tell you it does not have the bypass option anymore.

The 600 is not on the same power outlet, but is on an outlet that is 10ft from the receiver outlet, and they are wired togethor. I don't get the noise then. It is only when I plug the other subs to the 600's Line Out Coax. I don't even think they have to be plugged in, but I'll have to test that again another night.

I would I plug everything into one outlet, an outlet only has 2 ports (or whatever you want to call them). In my AV closet I have 2 outlets side by side in a Box that accomodates 2 outlets for a total of 4 plugs. Between my Tripplitte surge protector, Odyssey amps, and HTPC,, they are all taken up.

If Outlets are wired side by side, how is that any different than outlets that are wired the same way but have longer runs of 12-2 wiring? How can a person plug everything into 1 outlet, if subs are clear across the room?

I've tested all my outlets with a tester and it shows wiring is correct.

If it has 150hz instead of by-pass, then I'm sure it's the new firmware.

3 subs may blow you out of the room if they are mis-adjusted and you are sitting right at a sweet spot. 3 subs should however result in bass the has nearly equal SPL no matter where you sit in the room provided they are properly tweaked.

Think back to physics ripple tank experiments. Now you have to master the ripples young Padawan .

I am not suggesting that you leave them all plugged into one receptacle permanently. This is simply temporary in order to see if the problem can be alleviated through the use of a single connection. So plug a power bar into a single receptacle and branch off with a few extension cords to see if the buzzing goes away. You have to make sure that the Denon is also plugged into this power bar as you want the subs and the Denon to share the same ground. Don't turn them up too loud either because you may trip the breaker.

John, I forgot to mention I've gone back/forth on using your method of dialing in each sub 5dB below, and then turning them all on, and calibrating them all the same as the other speakers.

The reason why the change is that when listening to music, I was just not getting the WoW affect in the lowww end. Ian's video mentioned to calibrate them all the same, and this seems to give me the lows I would expect from subs. 3 subs should blow me out of the room, and they are not. the only time is if I put on some of those Bass Subwoofer test songs on youtube.

Mojo, I have the new amp but not sure if it is the new firmware, I can tell you it does not have the bypass option anymore.

Ok well it depends how hot you want the sub system. I run 4 subs in total calibrated equal to my centre speaker ie 75hz. To get there I have to calibrate each sub to 65-66hz, which leaves lots of room and output in reserve for Pulse, WoTW type stuff. At combined 75hz, I know where reference is on my system. For music and concert DVDs its fine right there but for HT action flicks I usually bump it another 3 db. In my smaller sealed treated room the subs really pressurize the HT and flap the pants as they say. But when I shut down my system everything reverts to my reference 75db setting.

Besides the headroom, the subs provide the smooth FR across more seats. I wouldn't want them to overpower the rest of the speakers or blow me out of the room. Heck, if that is the objective just crank up one sub and always sit in the sweet spot.

I agree with Mojo about the best way to reduce the hum...try to get all electricity from the same receptacle which avoids ground loops.

The problem, and I think Mojo is having this as well, is I can't dial in the subs below as your saying. To get the 600 5dB's below, say 70hz the gain on the receiver AND 600 have to be at MIN. This causes a problem for the 350's as you have to crank them to the MAX which I'm having difficult to achieve.

On the flipside, If I use a higher target SPL, say 80dB, then I have to crank my other speakers so high on the receiver levels, like +12 or more which can't bedone.

I don't know if any of this makes sense or not. I think the problem may have to do with the 600 sucking all the power from the Denon, not sure.